Optimized short message transport

ABSTRACT

A method for transferring data using optimized short message transport includes receiving at a first network node an attach request message. The attach request message includes short-message data. The first network node receives from a second network node a short-message data response message. The short-message data response message includes at least one of an address for a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, or a short-message entity destination address.

TECHNICAL FIELD

This disclosure relates to data transmission in wireless communication systems and, more specifically, to optimized short message transport in a cellular Internet of Things environment.

BACKGROUND

In some cases, a cellular Internet of Things (CIoT) is a scenario that a large number of devices, e.g., millions or billions of devices, may be served by a wireless network. The devices may range from stationary devices deep in basements to devices that have limited mobility speed. The devices may send and/or receive infrequent, small amounts of data. Examples of CIoT devices may include smart utility meters such as gas, water, or electric meters that may autonomously report utility usage to the utility provider via the wireless network. Other example of CIoT devices may include environmental monitoring sensors that may be placed randomly in a geographical area to monitor air or water quality. In some cases, short message service (SMS) may be used for a device to send and/or receive a short message up to 140 bytes/octets in length. The infrequent and small amount of CIoT data may be included in the short message and delivered to the network by SMS.

DESCRIPTION OF DRAWINGS

FIG. 1 is an example wireless communication system that uses optimized short message transport to transfer data in a CIoT environment according to an implementation.

FIG. 2 is a data flow diagram illustrating an example process for using optimized short message transport to transfer data in a CIoT environment according to an implementation.

FIG. 3 is a data flow diagram illustrating an example process for using optimized short message transport to transfer mobile-originated data in a CIoT environment according to an implementation.

FIG. 4 is a data flow diagram illustrating an example process for using optimized short message transport to transfer mobile-terminated data in a CIoT environment according to an implementation.

FIG. 5 is a data flow diagram illustrating another example process for using optimized short message transport to transfer mobile-terminated data in a CIoT environment according to an implementation.

FIG. 6 is a schematic diagram illustrating an example process of a user equipment (UE) including mobile-originated data in a Message 1 according to an implementation.

FIG. 7 is a schematic diagram illustrating an example process of a network node 1 extracting mobile-originated data from a Message 1 and including the data in a Message 7 according to an implementation.

FIG. 8 is a schematic diagram illustrating an example process of a network node 1 extracting mobile-terminated data from a Message 3 c and including the data in a Message 6 according to an implementation.

FIG. 9 is a schematic diagram illustrating an example process of a UE extracting mobile-terminated data from a Message 6 according to an implementation.

FIG. 10 is a schematic diagram illustrating an example process of a UE including mobile-originated data in a Message 1 without an SMS service center (SMSC) address according to an implementation.

FIG. 11 is a schematic diagram illustrating an example process of a network node 1 extracting mobile-originated data from a Message 1 and including the data in a Message 7, without a UE providing an SMSC address, according to an implementation.

FIG. 12 is a schematic diagram illustrating an example process of a network node 1 extracting mobile-terminated data from a Message 3 c and including the data in a Message 6 without an SMSC address, according to an implementation.

FIG. 13 is a schematic diagram illustrating an example process 1300 of a UE extracting mobile-terminated data from a Message 6 without an SMSC address according to an implementation.

FIG. 14 is a flowchart illustrating an example method for using optimized short message transport to transfer data in a CIoT environment according to an implementation.

FIG. 15 is a data flow diagram illustrating an example process to notify a network node 2 of a number of mobile-terminated messages pending according to an implementation.

FIGS. 16A-16E illustrate a first example description of Evolved Packet System (EPS) mobility management (EMM) procedures according to an implementation.

FIGS. 17A-17F illustrate a second example description of EMM procedures according to an implementation.

FIG. 18 illustrates a third example description of EMM procedures according to an implementation.

FIGS. 19A and 19B illustrate an example description of an attach accept message according to an implementation.

FIG. 20 illustrates an example description of an attach reject message according to an implementation.

FIGS. 21A and 21B illustrate an example description of an attach request message according to an implementation.

FIGS. 22A and 22B illustrate an example description of EMM cause according to an implementation.

FIG. 23 illustrates an example description of EPS attach type according to an implementation.

FIG. 24 illustrates an example description of a CIoT message container according to an implementation.

FIG. 25 illustrates an example description of data message container information element (IE) according to an implementation.

FIG. 26 illustrates an example description of pending messages IE according to an implementation.

FIGS. 27A-27C illustrate an example description of MAP_SEND_AUTHENTICATION_INFO service according to an implementation.

FIGS. 28A-28C illustrate an example description of MAP_UPDATE_LOCATION service according to an implementation.

FIGS. 29A-29C illustrate an example description of MAP_UPDATE_GPRS_LOCATION service according to an implementation.

FIGS. 30A-30C illustrate an example description of MAP-INSERT-SUBSCRIBER-DATA service according to an implementation.

FIGS. 31A and 31B illustrate an example description of MAP-REPORT-SM-DELIVERY-STATUS service according to an implementation.

FIG. 32 illustrates an example description of mobile service data type according to an implementation.

FIG. 33 is a schematic illustrating an example network node.

FIG. 34 is a schematic illustrating an example user equipment device.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The present disclosure is directed to optimized short message transport for transferring data in a CIoT environment. In some cases, CIoT devices may have limited power supply, e.g., powered by batteries. Examples of CIoT devices with limited power supply may include environmental monitoring sensors that are randomly placed in a geographical area to monitor air or water quality. In some cases, in order to deliver data up to 140 bytes/octets using SMS, it may take a large number of messages between the CIoT device and the network. In some cases, if Internet Protocol (IP)-based SMS is involved, even more messages may be needed and those messages maybe significantly bigger, e.g. using IP multimedia subsystem (IMS) to transport short messages. For example, when there is no data transfer, the CIoT device may be powered off or in a low battery consumption state and not connected to the network. When the CIoT device determines that there is a need to contact the network to either send, receive, or send and receive data, the CIoT device may power on or back to a normal battery consumption state and connect to the network. In order to connect to the network, the device may need to perform an attach procedure to register with the network. In some cases, a complete attach procedure may be performed before a short message (SM) can be delivered. To improve power efficiency of the CIoT device, an efficient short message transport with a reduced number of messages may be desirable. Reducing the number of messages may reduce the amount of time that the device connects to the network and hence save the power. Reducing the number of messages may also free up network resources so that more CIoT devices may be served by the network.

In some cases, a short message may be included in a message associated with an attach procedure to reduce the number of messages. However, in some cases, including a short message in another message may significantly increase the overall message size due to excessive protocol overhead. For example, if IP-based SMS is involved, the overall message size may be increased significantly due to various protocol headers. Therefore, it is desirable to have a small message size when including the short message. The device may use less power to process a message of a small size. Network resources may also be efficiently used by reducing message sizes.

To reduce the number of messages, the optimized short message transport may include data in a short message and include the short message in the messages associated with the attach procedure. In this case, the data may be delivered during the attach procedure without a bearer setup. In some cases, as discussed below, the CIoT device may disconnect from the network even before the attach procedure is completed if there is no data to be delivered to the device. To reduce the message size, the optimized short message transport may include data in SMS Protocol Data Units (PDUs) and include the SMS PDUs in the messages associated with the attach procedure without involving excessive protocol overhead.

FIG. 1 is an example wireless communication system 100 that uses optimized short message transport to transfer data in a CIoT environment according to an implementation. In some implementations, the attach procedure may be performed for a user equipment (UE, also known as CIoT device) to connect to the network. The attach procedure may include an authentication procedure and a location update procedure. The authentication procedure may be used for the UE and the network to perform mutual authentication of each other to avoid irresponsible usage of the network. The location update procedure may be used for the UE to update the location to the network and for the network to retrieve the services to which the UE is subscribed to, which could be, but not limited to at that location, such as roaming services.

In the example communication system 100, a first network node may receive an attach request message from a UE. The attach request message may include short-message data. The short-message data may be an SMS PDU, such as one of an SMS-SUBMIT PDU, an SMS-COMMAND PDU, an SMS-DELIVER-REPORT PDU, or an SMS-SUBMIT-REPORT PDU.

In the attach request message, the UE may include an indication of a type of data service that the UE requested. The type of data service may be one of but not limited to mobile origination (MO), mobile termination (MT), or mobile origination and termination. Mobile origination may refer to the service of the UE sending data to the network. Mobile termination may refer to the service of the UE receiving data from the network. Mobile origination and termination may refer to the service of the UE both sending and receiving data to and from the network. In the attach request message, the UE may also indicate that the UE request not to transition to a connected mode. Examples of MO, MT could be but not limited to MO SMS, MT SMS, etc.

In some implementations, the first network node may send a second message to a second network node. The second message may include an indication of the type of data service the UE requested. The second message may be one of an authentication request or a location update. If the UE requests at least mobile termination service (e.g., mobile termination or mobile origination and termination), the second network node may provide the information of whether there are mobile-terminated messages pending for the UE and/or the number of pending messages. If the UE requests at least mobile origination service (e.g., mobile origination or mobile origination and termination), the second network node may provide an address of a short message service center. In some implementations, the short-message data included in the attach request message may not need to include an address of a short message service center.

In some implementations, the first network node may receive from the second network node a short-message data response message. The short-message data response message may include at least one of an address of a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, an indication that indicates a number of mobile-terminated messages pending for the UE, or a short-message entity destination address, e.g., an international telecommunication union telecommunication (ITU-T) E.164 address (which may also be known as an Mobile Station International Subscriber Directory Number (MSISDN) or MSISDN number), session initiation protocol (SIP) uniform resource identifier (URI), etc. The short-message data response message may be an insert subscriber data (ISD). The ISD may be a message associated with the location update procedure.

In some implementations, the first network node may transmit an attach response message to the UE. The attach response message may include an indicator indicating whether a mobile-terminated message is pending for the UE and/or the number of pending messages. The attach response message may also include the mobile-terminated message.

In some implementations, the first network node may receive the short-message data response message from the second network node. Based on the address of the short message service center included in the short-message data response message, the first network node may determine the short message service center. The first network node may transmit the short-message data from the UE to the short message service center.

In some implementations, the first network node may transmit an authentication request to the UE. The authentication request may indicate whether a mobile-terminated message is pending for the UE. For example, if the UE requested mobile termination and there is no pending message for the UE, the UE may disconnect from the network without performing the remaining authentication and attach procedures.

Using optimized short message transport to transfer data according to methods and systems described herein may provide one or more advantages. For example, the optimized short message transport may deliver the data during the attach procedure without a bearer setup. Having the UE indicate to the network the type of data service may enable the network to further optimize behavior. For example, if the UE requests mobile termination and there is no message pending for the UE, the network may let the UE disconnect from the network without finishing the authentication and attach procedures. Reducing the time that the UE connects to the network may significantly save the UE power and make the network resources available to serve more UEs. To reduce message size, data may be included in SMS PDUs and sent with the messages associated with the attach procedure without involving excessive protocol overhead. The UE saves battery power when processing a message with a reduced message size. In some cases, if the UE requests at least mobile origination service, the UE may not include the SMS service center (SMSC) address in the message. Instead, the network may provide the SMSC address. Removing SMSC address may further reduce the message size.

In some implementations, unstructured supplementary service data (USSD) may also be used to deliver the small amount of data in a CIoT environment. A USSD message may include up to 182 alphanumeric characters. The optimized short message transport described for SMS in this application may also apply to USSD.

In some implementations, the service of mobile origination may be referred to SMS/USSD origination. The service of mobile termination may be referred to SMS/USSD termination. The service of mobile origination and termination may be referred to SMS/USSD origination and termination.

At a high level, the example wireless communication system 100 includes a wireless communication network 104, which includes or is communicably coupled with a network node 1 106, a network node 2 108, and a network node 3 110. The example wireless communication system 100 also includes a UE 102 that connects to the network node 1 106. The UE 102 may be a CIoT device that sends and/or receives infrequent and small amount of data. In some implementations, a communications system can include additional or different components and features and can be configured in a different manner than the example system 100 shown in FIG. 1. For example, one UE is shown in FIG. 1 for clarity and brevity, but many UEs can be included in the system 100.

The network node 1 106 may be a Mobility Management Entity (MME), a Serving General Packet Radio Service (GPRS) Support Node (SGSN), CIoT Signaling Gateway Node (C-SGN), Mobile Switching Center (MSC) and MME connected together, or others network nodes or entities. The UE may connect to the network node 1 106 via a base station or evolved Node B (eNB). The network node 1 106 may perform mobility management functions for the UE 102 and may have the knowledge of the location of the UE 102.

The network node 2 108 may be a Home Location Register (HLR), Home Subscriber Server (HSS), Authentication Center (AuC), Authentication, Authorization, and Accounting (AAA) server, Mission Critical Push To Talk (MCPTT) Server, MCPTT user data server, or other network nodes or entities. As discussed in detail below, the network node 2 108 may have the knowledge whether there are messages pending for the UE 102 and/or the number of messages pending. The network node 2 108 may also have the knowledge of the address of the network node 3 110. The network node 2 108 may include authentication function and subscriber database. In some implementations, the address of the network node 3 110 may be stored in the subscriber database. In a CIoT environment, the UE may send data to a fixed network node 3. For example, if the UE is a smart utility meter, it is likely that the UE may send utility usage reports to the server of the utility provider and that server may be associated with a fixed network node 3 110.

The network node 3 110 may be SMS Gateway Mobile Services Switching Center (SMS-GMSC), SMS Inter Working Mobile Switching Center (SMS-IWMSC), SMS router, Short Message Service-Service Centre (SMS-SC or SMSC), or other network nodes or entities. The network node 3 110 may be responsible for storing and forwarding short messages. For example, for mobile-terminated SMS, the network node 3 110 may store the short messages and forward to the UE 102 when the UE 102 is available to receive the short messages. For mobile-originated SMS, the network node 3 110 may store the short messages from the UE 102 and forward to the destination server or external networks.

In operation, the UE 102 may receive an indication from the wireless network 104 indicating whether the optimized short message transport is supported by the wireless network 104. If supported, the indication may further indicate which optimized short message transport the network supports (e.g., SMS over attach, USSD over attach, etc.). In some implementations, the indication could be implicit by discovery of a radio access technology (RAT) that is known to support the optimized short message transport. In some other implementations, the indication is broadcast to the UE 102 by the wireless network 104. Alternatively, the UE may not receive the indication and try the procedure of the optimized short message transport anyway, in which case the UE may store whether or not the procedure was successful. This storage may be used later when there is further data to send to the network.

When the UE 102 determines that there is a need to either send, receive, or send and receive data, the UE 102 may power on or back to the normal battery consumption state and connect to the wireless network 104. In order to connect to the wireless network 104, the UE 102 may need to perform an attach procedure to register with the wireless network 104.

The UE 102 may send an attach request message to the network node 1 106. In one embodiment, in the attach request message, the UE 102 may include an indication of the type of data service that the UE 102 requests. The type of data service may be one of but not limited to mobile origination, mobile termination, or mobile origination and termination. For example, if the UE 102 is a smart utility meter and would like to send the utility usage report to the utility provider, the UE 102 may indicate mobile origination in the attach request message. If the UE 102 connects to the network 104 to check for system updates or notifications, the UE 102 may indicate mobile termination in the attach request message. If the UE 102 would like to both send and receive data, the UE 102 may indicate mobile origination and termination. The UE 102 may have different reasons each time it wakes up and connects to the network 104. Depending on the reason, the UE 102 may sometimes indicate mobile origination, sometimes mobile termination, and sometimes mobile origination and termination. In some implementations, including the indication of the type of data service in the attach request message may also notify the network 104 that the UE 102 wants to attach to the network without performing a bearer setup.

If the UE 102 has data to send (e.g., mobile origination or mobile origination and termination), the UE 102 may include the data in an SMS PDU. The UE 102 may include the SMS PDU in the attach request message and send the attach request message to the network node 1 106. In some implementations, the UE 102 may not include the address of the network node 3 110 (e.g., SMSC) in the SMS PDU. As discussed in more detail below, the network node 1 106 may obtain the address of the network node 3 110 (e.g., SMSC) from the network node 2 108. In the attach request message, the UE 102 may also indicate that the UE 102 request not to transition to a connected mode after the attach procedure.

In some implementations, if the UE 102 requests mobile termination, the UE 102 may send an indication for SMS attach only and not include an SMS PDU in the attach request message.

The network node 1 106 may send a message to the network node 2 108 which includes the indication of the type of data service the UE 102 requested. The message may be an authentication request associated with the authentication procedure or a location update message associated with the location update procedure. Depending on the type of data service the UE requested, the network node 2 108 may provide related information. For example, if the UE requests at least mobile origination service (e.g., mobile origination or mobile origination and termination), the network node 2 108 may provide the address of the network node 3 110 (e.g., SMSC). If the UE 102 requests at least mobile termination service (e.g., mobile termination or mobile origination and termination), the network node 2 108 may provide the information of whether there are messages pending for the UE 102 and/or the number of pending messages. If there are pending messages for the UE 102 and the UE 102 requested at least mobile termination service, the network node 2 108 may notify the network node 3 110 that the UE 102 is available to receive the pending messages, and in turn, the network node 3 110 may forward the pending messages to the network node 1 106.

The network node 2 108 may send a short-message data response message to the network node 1 106 and provide information related to the data service the UE 102 requested. The short-message data response message may be an insert subscriber data (ISD) message associated with the location update procedure. If the UE 102 requested at least mobile termination service, the short-message data response message may indicate whether there is a message pending for the UE 102 and/or the number of pending messages. If the UE 102 requests at least mobile origination service, the short-message data response message may include the address of the network node 3 110 so that the network node 1 106 may forward the mobile-originated data to the network node 3 110. In some implementations, the short-message data response message may be an authentication vectors response message associated with the authentication procedure that may indicate whether there are pending messages for the UE and/or the number of pending messages.

In some implementations, the network node 1 106 may send an authentication request to the UE 102. The authentication request may indicate whether there is a message pending for the UE 102. If there is no pending message for the UE 102 and the UE 102 requested mobile termination, the UE 102 may disconnect from the network without performing the remaining authentication procedure and attach procedure to save power.

In some implementations, after successful authentication, the network node 1 106 may transmit an attach response message to the UE 102. The attach response message may indicate whether there are mobile-terminated messages pending for the UE 102. The attach response message may also include the mobile-terminated message which includes the data to be delivered to the UE 102. In some implementations, if the data can be fit into the single attach response message, the attach response message may be an attach reject and the UE 102 may disconnect from the network after receiving the data from the attach reject.

FIGS. 2-9 and associated descriptions provide additional details for example implementations. One skilled in the art will appreciate that the implementations can be mixed and matched.

Turning to a general description of the elements, a UE may be referred to as a mobile electronic device, user device, mobile station, subscriber station, portable electronic device, mobile communications device, wireless modem, wireless terminal, mobile equipment, session initiation protocol (SIP) user agent, set-top box, test equipment, embedded modem, or CIoT device. Examples of a UE may include a cellular phone, personal data assistant (PDA), smart phone, laptop, tablet personal computer (PC), pager, portable computer, portable gaming device, wearable electronic device, or other mobile communications device having components for communicating data via a wireless communication network. The wireless communication network may include a wireless link over at least one of a licensed spectrum and an unlicensed spectrum.

Other examples of a UE include mobile and fixed electronic devices. A UE may include a Mobile Equipment (ME) device and a removable memory module, such as a Universal Integrated Circuit Card (UICC) that includes a Subscriber Identity Module (SIM) application, a Universal Subscriber Identity Module (USIM) application, or a Removable User Identity Module (R-UIM) application. The term “UE” can also refer to any hardware or software component that can terminate a communication session for a user. In addition, the terms “user equipment,” “UE,” “user equipment device,” “user agent,” “UA,” “user device,” and “mobile device” can be used synonymously herein.

The wireless communication network 104 may include one or a plurality of radio access networks (RANs), other access networks such as fixed Ethernet or IEEE 802.11 WLAN, core networks (CNs), and external networks. The RANs may comprise one or more radio access technologies. In some implementations, the radio access technologies may be Global System for Mobile communication (GSM), Interim Standard 95 (IS-95), Universal Mobile Telecommunications System (UMTS), CDMA2000 (Code Division Multiple Access), Evolved Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), or LTE-Advanced. In some instances, the core networks may be evolved packet cores (EPCs). The core networks may include Mobility Management Entity (MME), a Serving General Packet Radio Service (GPRS) Support Node (SGSN), CIoT Signaling Gateway Node (C-SGN), Mobile Switching Center (MSC) and MME connected together, Home Location Register (HLR), Home Subscriber Server (HSS), Authentication Center (AuC), PS-UDF, Authentication, Authorization, and Accounting (AAA) server, SMS Gateway Mobile Services Switching Center (SMS-GMSC), Inter Working Mobile Switching Center (IWMSC), SMS router, SMSC, or other network nodes or entities.

The wireless network 104 may be a CIoT network dedicated to serve CIoT devices. In some implementations, the CIoT network may have its own frequency spectrum and network nodes. In some implementations, the CIoT network may be part of another network (e.g., a GSM, UMTS, CDMA2000, UMTS, or LTE network) and share the frequency spectrum and network nodes with the other network.

While elements of FIG. 1 are shown as including various component parts, portions, or modules that implement the various features and functionality, nevertheless these elements may instead include a number of sub-modules, third-party services, components, libraries, and such, as appropriate. Furthermore, the features and functionality of various components can be combined into fewer components as appropriate.

FIG. 2 is a data flow diagram illustrating an example process 200 for using optimized short message transport to transfer data in a CIoT environment according to an implementation. The data flow diagram includes the UE 102, the network node 1 106, the network node 2 108, and the network node 3 110. The data flow diagram also includes Messages 1, 2, 3 a-3 e, and 4-7 corresponding to operations 1, 2, 3 a-3 e, and 4-7. One skilled in the art will appreciate that operations 1, 2, 3 a-3 e, and 4-7 may be concurrent, simultaneous, or overlapping events. The following table lists the possible network nodes for the network node 1 106, the network node 2 108, and the network node 3 110. The table also lists the possible messages for Messages 1, 2, 3 a-3 e, and 4-7 corresponding to operations 1, 2, 3 a-3 e, and 4-7.

TABLE 1 Description of network nodes and messages Descriptive term Possible node/message Characteristics UE ME, SIP UA, set-top box, test equipment, embedded modem Network MME, SGSN, C-SGN, MSC and MME connected Node 1 together (e.g., using a SGs interface), etc Network HLR, HSS, AuC, AAA, MCPTT user data server, May include Node 2 MCPTT server Authentication function Subscriber database Network SMS-GMSC, IWMSC, SMS Router, SMSC Node 3 Message 1 Attach Request, The message includes an identity of the subscriber the data to be conveyed in the message, e.g., Data 1 The UE may not need to go into connected mode. The message may trigger authentication function to be performed. Message 2 MAP_SEND_AUTHENTICATION_INFO request/indication Diameter Authentication-Information-Request (AIR) Message 3a MAP_SEND_AUTHENTICATION_INFO response/confirm Diameter Authentication-Information-Answer (AIA) Message 3b MAP-ALERT-SERVICE-CENTRE request/indication MAP-INFORM-SERVICE-CENTRE request Diameter Alert-Service-Centre-Request (ALR) Message 3c MAP-MT-FORWARD-SHORT-MESSAGE request/indication Diameter MT-Forward-Short-Message-Request (TFR) SIP MESSAGE method SIP INVITE method Message 3d MAP_UPDATE_LOCATION request/indication MAP_UPDATE_GPRS_LOCATION request/indication Diameter Update-Location-Request (ULR) Message 3e MAP-INSERT-SUBSCRIBER-DATA request/indication Diameter Insert Subscriber Data-Request (IDR) MAP_UPDATE_LOCATION response/confirm MAP_UPDATE_GPRS_LOCATION response/confirm Diameter Update-Location-Answer (ULA) Message 4 Authentication Request Attach Reject Message 5 Authentication Response, Authentication Reject Message 6 Attach Reject, Attach Accept, Detach Request Message 7 MAP-MO-FORWARD-SHORT-MESSAGE request/indication Diameter MO-Forward-Short-Message-Request (OFR) SIP MESSAGE method SIP INVITE method Message 10 MAP-REPORT-SM-DELIVERY-STATUS request/indication Message 11 MAP-REPORT-SM-DELIVERY-STATUS response/confirm

Data sent from the UE 102 to the network may be referred to Data 1 (i.e., mobile-originated data). Data sent from the network to the UE 102 may be referred to Data 2 (i.e., mobile-terminated data). In some implementations, Data 1 may be one of the following SMS PDUs: an SMS-SUBMIT PDU, an SMS COMMAND PDU, an SMS DELIVER REPORT PDU, or an SMS SUBMIT REPORT PDU. Data 2 may be one of the following SMS PDUs: an SMS-DELIVER PDU, an SMS STATUS REPORT PDU, an SMS DELIVER REPORT PDU, or an SMS SUBMIT REPORT PDU.

As shown in FIG. 2, before operation 1, the UE 102 may be in idle mode or in a low battery consumption state and the UE 102 is not connected or attached to the network. The UE 102 may determine that it needs to contact the network to either send, receive, or send and receive data. The UE 102 may receive an indication that the network supports sending data in an optimized way (e.g., optimized short message transport for SMS or USSD) in its first Non-Access Stratum (NAS) signalling message sent to the network. In some implementations, the indication may be implicit by the RAT type of the network. For example, the optimized short message transport may be supported on a particular RAT. The UE 102 may also receive the indication via a broadcast message from the network that includes a code point(s) that identifies the optimized short message transport supported. The optimized short message transport may be one or more of SMS over attach, USSD over attach, or SMS/USSD over attach.

At operation 1, the UE 102 may send a Message 1 to the network node 1 106 (e.g., C-SGN, MME, etc.). Message 1 may be an attach request message. Message 1 may include an identifier identifying the UE 102. The identifier may be a type of private identity such as an Internal Mobile Subscriber Identity (IMSI) or a Globally Unique Temporary Identity (GUTI). If the UE 102 wants to send data, the mobile-originated data may be included in an SMS PDU. In some implementations, Message 1 may also include an indication of the type of data service the UE 102 requested. The data service may be one of but not limited to mobile origination, mobile termination, or mobile origination and termination. In some implementations, including the indication of the type of data service in Message 1 may notify the network that the UE 102 wants to attach to the network without performing a bearer setup.

In some implementations, Message 1 may not include the following short message information elements: short message service center address (SMSC address) and short message entity destination address (SME TP-DA). In the SME TP-DA, Type of Number (TON) and Numbering Plan Identification (NPI) may be both set as “unknown” with address length of zero digits. One skilled in the art will appreciate that any code point settings in TON and NPI could be used as long as the network knows that these settings imply no SME TP-DA is included.

In some implementations, Message 1 may include an indication that the UE 102 does not want to transition into CONNECTED mode after the attach procedure. In some implementations, the indication may be implicitly derived from the data service the UE 102 requested.

In some implementations, the indication of the data service requested may be a new code point in an existing information element, a new information element, or could be a specific set (1 to many) characters in the access point name (APN) information element. In some implementations, the code point for the indication of the data service the UE requested are such that the network node 1 106 does not set up an IP bearer.

Upon the network node 1 106 receiving Message 1, if the UE 102 needs to be authenticated, then the network node 1 106 performs authentication procedures as shown in operations 2 a, 3 a, 4, and 5.

At operation 2, the network node 1 106 may send a Message 2 to the network node 2 108 (e.g., HSS etc.). Message 2 may be an authentication request. Message 2 may include the UE identifier (e.g., the private identity such as IMSI, GUTI) that was received in Message 1 as well as the address of the network node 1 106 (e.g., Global Title, E.164 number, uniform resource locator, etc.). In some implementations, Message 2 may also include the type of data service the UE requested that could have been received in Message 1.

In some implementations, the network node 2 108 includes an authentication function, e.g., HSS with authentication function. When the network node 2 108 receives Message 2 and determines that the UE 102 is not authorized to perform the requested data service, the network node 2 108 may respond with a reject message back to the network node 1 106.

When the network node 2 108 receives Message 2 and determines that the UE 102 is authorized to perform the requested data service, the network node 2 108 may perform either one or both of the following: (1) The network node 2 108 may generate or create authentication vectors to be sent to the UE 102; (2) If the network node 2 108 has an indication that there are pending messages to be sent to the UE 102 and the UE 102 has indicated that it is connecting to the network for at least mobile termination service, the network node 2 108 may send a notification to the network node 3 110 (e.g., SMSC etc.) to indicate that the UE 102 is available to receive the pending messages. For example, as discussed below, the network node 2 108 may send a Message 3 b to the network node 3 110.

At operation 3 a, the network node 2 108 may send a Message 3 a to the network node 1 106. Message 3 a may be a short-message data response. Message 3 a may include the authentication vectors generated by the network node 2 108. Message 3 a may also include an indication whether there are pending messages to be delivered to the UE 102 and/or the number of messages pending which could range from 0 to many.

In some implementations, if the UE 102 requested mobile termination and there are no pending messages for the UE 102, Message 3 a could either include an indication that there are no pending messages or could be a reject message with an optional cause value “no pending messages.”

At operation 3 b, the network node 2 108 may send a Message 3 b to the network node 3 110. In some implementations, Message 3 b is sent because of receipt of Message 2 and the data service requested indicated in Message 2 was at least mobile termination service. In some implementations, Message 3 b is sent because of receipt of Message 3 d, as discussed in detail below, and the data service requested indicated in Message 3 d was at least mobile termination service. In some implementations, Message 3 b is sent if the UE requested at least mobile termination service and the network node 2 108 knows that there are pending messages for the UE. In some implementations, the purpose of Message 3 b is to notify the network node 3 110 that the UE 102 is available to receive the pending messages so that the network node 3 110 may send the pending messages to the network node 1 106 and the network node 1 106 may further send the pending messages to the UE 102.

Message 3 b may include a UE identifier for the UE 102. The UE identifier in Message 3 b may be a different identifier from the one in Messages 1 and 2. In some implementations, the UE identifier in Message 3 b may be a public UE identity such as Mobile Station International Subscriber Directory Number (MSISDN) or uniform resource identifier (URI). Message 3 b may also include the address of the network node 1 106 (e.g., Global Title, E.164 number, URL, etc.). In some implementations, by conveying the address of the network node 1 106 (e.g., C-SGN or MME which is responsible for UE mobility functions and has knowledge of the UE location), the network node 3 110 may know how to send the pending messages to the UE 102. For example, the network node 3 110 may send the pending messages to the network node 1 106 and the network node 1 106, which knows the UE location, may further forward the pending messages to the UE 102.

At operation 3 c, the network node 3 110 (e.g., SMSC) may send one or more Message 3 c to the network node 1 106. Upon receiving Message 3 b indicating that the UE 102 is available to receive pending messages, the network node 3 110 may create Message 3 c. Depending on the amount of data to send, the network node 3 110 may send one Message 3 c or a plurality of Message 3 c. Each Message 3 c may include a UE identifier (e.g., the public identity such as MSISDN or URI) and the data to be delivered to the UE. The data to the UE may be included in SMS PDUs. After receiving Message 3 c, the network node 1 106 may store the data for the UE 102.

At operation 3 d, the network node 1 106 may send a Message 3 d to the network node 2 108. Message 3 d may be a location update. If Message 2 did not include the type of data service the UE requested or Message 3 a does not include the indication whether there is pending messages for the UE, the network node 1 106 may send Message 3 d. Message 3 d may include one or more of the UE identifier (e.g., the private identity IMSI or GUTI) that was received in Message 1, the address of the network node 1 106 (e.g., Global Title, E.164 number, URL, etc.), or the type of data service the UE requested. One skilled in the art will appreciate that operation 3 d will normally happen after operation 5.

When the network node 2 108 receives Message 3 d, if the network node 2 108 has an indication that there are pending messages to be sent to the UE and the UE has indicated that it is connecting to the network for at least mobile termination service, the network node 2 108 may send a notification to the network node 3 110 indicating that the UE is available to receive the pending data. For example, the network node 2 108 may send Message 3 b to the network node 3 110.

At operation 3 e, the network node 2 108 may send a Message 3 e to the network node 1 106. Message 3 e may be a short-message data response. Message 3 e may include one or more of an indication that there are pending or no pending messages to be delivered to the UE, the number of messages pending which could range from 0 to many, the SMSC address to be used to send the mobile-originated data to, or the short message entity (SME) destination address to be used within the SMS message.

In some implementations, if the UE 102 requested mobile termination and there are no pending messages for the UE 102, Message 3 e could either include an indication that there are no pending messages or could be a reject message with an optional cause value “no pending messages.”

At operation 4, the network node 1 106 may send a Message 4 to the UE 102. In some implementations, the network node 1 106 sends Message 4 upon receiving Message 3 a. Message 4 may not have to wait for Message 3 d to be sent and Message 3 e to be received. Message 4 may include the authentication vectors. Message 4 may also include the indication that there are pending or no pending messages to be delivered to the UE or the number of messages pending which could range from 0 to many.

In some implementations, if the UE 102 requested mobile termination and there are no pending messages for the UE 102, Message 4 could either include an indication that there are no pending messages or could be a reject message, for example, an attach reject with an optional cause value “no pending messages.”

In some implementations, if Message 3 a or Message 3 e is a reject message with optional cause value “no pending messages,” Message 4 may also be a reject message with an optional cause value “no pending messages.”

Upon receiving Message 4, the UE 102 may perform the authentication based on the authentication vectors received in Message 4. Upon the UE 102 validating that the authentication challenge based on the authentication vectors is a legitimate one, if Message 4 includes an indication that there are pending messages and the UE requested at least mobile termination service, the UE 102 may store the indication of the pending messages and/or the number of pending messages, which could range from 0 to many. In some implementations, if Message 4 includes an indication that there is no pending message and the UE requested mobile termination, the UE 102 may not perform the rest of the authentication and attach process and return to IDLE state.

At operation 5, the UE 102 sends a Message 5 to the network node 1 106. For example, Message 5 may include the authentication response associated with the authentication vectors received in Message 4. Based on the authentication response received in Message 5, the network node 1 106 may determine whether the authentication process is successful or not. For example, the authentication process is successful if the authentication response received in Message 5 matches the authentication response stored in the network node 1 106 which was received from Message 3 a.

At operation 6, the network node 1 106 may send a Message 6 to the UE 102. Message 6 may be an attach response message. Upon a successful authentication, if the UE requested at least mobile termination service (e.g., mobile termination, mobile origination and termination), the network node 1 106 may determine if there are pending messages to be delivered to the UE. For example, if the network node 1 106 has not received an indication in Message 3 a or Message 3 e indicating pending messages or the network node 1 106 has not received any Message 3 c including pending messages, the network node 1 106 may determine that there is no pending message for the UE. If the network node 1 106 has pending messages stored from one or more received Message 3 c, the network node 1 106 may determine that there are pending messages for the UE 102.

If the UE 102 requested at least mobile termination service and there is no pending message for the UE, and, if the UE has sent mobile-originated data in Message 1 and the mobile-originated data has been received by the network, then Message 6 could be an attach reject with indications indicating “successful receive of data” and “no pending terminated messages.” After receiving the attach reject, the UE 102 may disconnect from the network.

If the UE 102 requested at least mobile termination service and there is no pending message for the UE, and, if network node 1 106 has received an indication in Message 1 indicating at least mobile origination service but no mobile-originated data was received, then Message 6 could be an attach reject with a cause value indicating an error. After receiving the attach reject, the UE 102 may detach or disconnect from the network and attempt the procedure in FIG. 2 again.

If the UE requested the service of mobile termination and there is no pending message for the UE, Message 6 could be an attach reject with cause “no pending terminated messages.” After receiving the attach reject, the UE 102 may disconnect from the network.

If the UE requested at least mobile termination service and there are pending messages stored at the network node 1 106, and, if the mobile-terminated data that was received in the one or more Message 3 c fits into a single Message 6, and, if the UE has sent the mobile-originated data in Message 1 and the mobile-originated data was received by the network, then Message 6 may include indications indicating “successful receive of data” and include the mobile-terminated data. In some implementations, Message 6 may be an attach reject and the UE 102 may disconnect from the network after receiving the mobile-terminated data from the attach reject.

If the UE requested at least mobile termination service and there are pending messages stored at the network node 1 106, and, if the mobile-terminated data that was received in the one or more Message 3 c does not fit into a single Message 6, and, if an indication was received in Message 1 that UE wants to move into CONNECTED mode or no such indication was received, then the network node 1 106 may send either of the followings to the UE 102: (i) Message 6 (e.g., an attach accept); (ii) Message 6 (e.g., an attach accept) with an indication indicating pending data to be sent; (iii) Message 6 (e.g., an attach accept) with an indication of the number of pending messages to be sent back; (iv) Message 6 (e.g., an attach accept) including mobile-terminated data from one Message 3 c, e.g., the first Message 3 c received, and an indication that further data is to be sent or the number of pending messages to be sent back. In some implementations, if the UE 102 receives an attach accept, the UE 102 may revert to legacy handling for at least mobile termination services. The UE 102 may stay attached to the network until the UE 102 receives the number of short messages as identified in Message 4 or Message 6. In some implementations, the UE 102 may stay attached to the network for a period of time that is implementation-dependant or network-provided.

If the UE requested at least mobile termination service and there are pending messages stored at the network node 1 106, and, if the mobile-terminated data that was received in the one or more Message 3 c does not fit into a single Message 6, and, if an indication was received in Message 1 that the UE 102 does not want to move into CONNECTED mode and stay in IDLE, then the network node 1 106 may send either of the followings to the UE 102: (i) Message 6 (e.g., an attach reject); (ii) Message 6 (e.g., an attach reject) with an indication that pending data to be sent; (iii) Message 6 (e.g., an attach reject) with an indication with number of pending messages to be sent back; (iv) Message 6 (e.g., an attach reject) including data from one Message 3 c, e.g., the first Message 3 c received, and an indication that further data is to be sent or the number of pending messages to be sent back. In some implementations, if the UE 102 receives an attach reject with an indication of pending messages or a number of pending messages to be sent, the UE 102 will then repeat the procedure in FIG. 2 from operation 1. When repeating the procedure, the UE 102 may request at least mobile termination service and optionally not send the indication of not to transition to a CONNECTED mode.

If the UE 102 moves into CONNECTED mode, the network node 1 106 may revert back to legacy SMS delivery behavior to deliver the pending messages. For pending short messages, this may be legacy SMS procedures to deliver the pending short messages. In some implementations, the network node 1 106 may not send any additional messages.

If in Message 1 the UE requested mobile origination, and, if mobile-originated data was sent in Message 1 and was received by the network, then Message 6 may include an indication indicating “successful receive of data.”

If in Message 1 the UE requested mobile origination but no mobile-originated data was included in Message 1, then Message 6 may be sent with a cause value indicating an error “data not received.”

In some implementations, for each successful message delivery for mobile-terminated data, the network node 1 106 may create a Call Detail Record (CDR) that includes an indication that could include any or none of the following: type of data received in Attach (e.g., SMS, USSD), data type within that type (e.g., SMS-DELIVER), or size of the data.

At operation 7, upon a successful authentication after operation 5, the network node 1 106 may send a Message 7 to the network node 3 110. Message 7 may include the mobile-originated data received from Message 1. In some implementations Message 7 may only be sent upon receipt of Message 3 e.

In some implementations, if the mobile-originated data in Message 1 is an SMS message, the network node 1 106 may extract the SMS PDU (e.g., SMS-SUBMIT) and insert it into a MAP_MO_FORWARD_SHORT message. If the SMSC address was not received from the UE 102 in Message 1 and an SMSC address was received in Message 3 e, the network node 1 106 may use the SMSC address that was received in Message 3 e in Message 7. If an SME destination address was received in Message 3 e, the network node 1 106 may insert the received SME destination address into the SMS-SUBMIT TP-DA information element that is sent in Message 7.

In some implementations, for each successful message delivery for mobile-originated data, the network node 1 106 may create a Call Detail Record (CDR) with an indication that could include any or none of the following: type of data received (e.g., SMS, USSD), data type within that type (e.g., SMS-SUBMIT), or size of the data.

In some implementations, the number of messages to send and/or receive by the UE before the UE detaches or disconnects from the network may include SMS messages that are marked as concatenated SMS messages.

FIG. 3 is a data flow diagram illustrating an example process 300 for using optimized short message transport to transfer mobile-originated data in a CIoT environment according to an implementation. The data flow diagram includes a UE 302, a CIoT base station/evolved Node B (C-BS/eNB) 304, a C-SGN 306, an SMSC/IWMSC 308, an HSS 310, and a packet data network gateway (P-GW) 312. The C-BS/eNB 304 may provide radio connection with the UE 302. The C-SGN 306 may be the network node 1 106. The SMSC/IWMSC 308 may be the network node 3 110. The HSS 310 may be the network node 2 108. The P-GW 312 may connect the UE 302 with the various external data networks such as Internet. FIG. 3 illustrates the scenario that the UE 302 attaches to the network to send mobile-originated data without performing a bearer setup and the UE 302 includes the mobile-originated data in the SMS PDU.

At operation 1, the UE 302 sends initial attach with “MO SMS” in order to signify that it wants to register without creating a packet data network (PDN) connection and includes SMS PDU as specified in 3GPP TS 23.040 e.g. SMS-SUBMIT. This follows the 3GPP TS 23.401 attach procedure with an extra indicator “MO SMS” in order to indicate that the UE wants to attach without immediately establishing a PDN connection and includes an SMS PDU. The UE 302 may initiate a PDN connection set up at a later stage if needed. The “MO SMS” indicator indicates the data service of mobile origination.

At operation 2, the C-SGN 306 processes the initial attach and identifies that the UE does not want to establish a PDN connection and wants to send an MO SMS; therefore, it does not further follow the initial attach procedures towards the P-GW 312 as defined in TS 23.401.

At operation 3, the C-SGN 306 authenticates the UE 302 following normal procedures.

At operation 4, the C-SGN 306 performs a Location Update to the HSS 310 including the reason for Location Update, e.g., MO SMS. If the UE 302 is authorized to perform MO-SMS, then the HSS 310 will either send the subscription information to the C-SGN 306 or send back a Location Update acknowledgement with an indication that the UE 302 is authorized for MO SMS.

At operation 5, the C-SGN 306 establishes UE context indicating to RAN node that signaling radio bearer (SRB) is needed and without requesting data radio bearers (DRBs) to be established

At operations 6 and 7, radio resource control (RRC) message establishes SRB.

At operation 8, S1 message is acknowledged.

At operation 9, the C-SGN 306 sends Attach Reject with “indication indicating SMS PDU was received and accept” to the UE 302.

At operation 10, the C-SGN 306 sends the SMS PDU using existing procedures to the SMSC 308.

FIG. 4 is a data flow diagram illustrating an example process 400 for using optimized short message transport to transfer mobile-terminated data in a CIoT environment according to an implementation. The data flow diagram includes a UE 302, a C-BS/eNB 304, a C-SGN 306, an SMSC/IWMSC 308, an HSS 310, and a P-GW 312. FIG. 4 illustrates the scenario that the UE 302 attaches to the network to determine if there is any mobile-terminated data. FIG. 4 also illustrates the scenario that the UE 302 attaches to the network to receive mobile-terminated data without performing a bearer setup and the mobile-terminated data can be fit into a single message.

At operation 1, the UE 302 sends initial attach with “MT SMS” in order to signify that it wants to register without creating a PDN connection. This follows the TS 23.401 attach procedure with an extra indicator “MT SMS” in order to indicate that the UE wants to attach without immediately establishing a PDN connection and wants a pending SM to be delivered. The UE 302 may initiate a PDN connection set up at a later stage if needed. The “MT SMS” indicator indicates the data service of mobile termination.

At operation 2, the C-SGN 306 processes the initial attach and identifies that the UE 302 does not want to establish a PDN connection and wants to receive MT SMS; therefore, it does not further follow the initial attach procedures towards the P-GW 312 as defined in TS 23.401.

At operation 3, the C-SGN 306 authenticates the UE 302 following normal procedures.

At operation 4, the C-CSGN 306 performs a Location Update to the HSS 310 including the reason for Location Update, e.g., MT SMS. If the UE 302 is authorized to perform MT-SMS, then the HSS 310 will inform the C-SGN 306 if there are or no pending messages to be delivered. If there are no messages, then operation 12 will be performed.

At operation 5, the C-SGN 306 establishes UE context indicating to RAN node that SRB is needed and without requesting DRBs to be established.

At operations 6 and 7, RRC message establishes SRB.

At operation 8, S1 message is acknowledged.

At operation 9, the HSS 310 alerts the SMSC 308 that the UE is available per procedures defined in 3GPP 29.002.

At operation 10, the SMSC 308 sends the SMS PDU to the C-SGN 306.

At operation 11, when the C-SGN 306 receives the SMS PDU from the SMSC 308, the C-SGN 306 sends Attach Reject with including the SMS PDU e.g. SMS-DELIVER as defined in 3GPP TS 23.040 to the UE 302.

At operation 12, the C-SGN 306 sends an Attach Reject including an indication that there are no messages to send.

FIG. 5 is a data flow diagram illustrating another example process 500 for using optimized short message transport to transfer mobile-terminated data in a CIoT environment according to an implementation. The data flow diagram includes a UE 302, a C-BS/eNB 304, a C-SGN 306, an SMSC/IWMSC 308, an HSS 310, and a P-GW 312. FIG. 5 illustrates the scenario that the UE 302 attaches to the network to determine if there is any mobile-terminated data. FIG. 5 also illustrates the scenario that the UE 302 attaches to the network to receive mobile-terminated data without performing a bearer setup and the mobile-terminated data cannot be fit into a single message.

At operation 1, the UE 302 sends initial attach with “MT SMS” in order to signify that it wants to register without creating a PDN connection. This follows the TS 23.401 attach procedure with an extra indicator “MT SMS” in order to indicate that the UE wants to attach without immediately establishing a PDN connection and wants a pending SM to be delivered. The UE 302 may initiate a PDN connection set up at a later stage if needed. The “MT SMS” indicator indicates the data service of mobile termination.

At operation 2, the C-SGN 306 processes the initial attach and identifies that the UE 302 does not want to establish a PDN connection and wants to receive MT SMS; therefore, it does not further follow the initial attach procedures towards the P-GW 312 as defined in TS 23.401.

At operation 3, the C-SGN 306 authenticates the UE 302 following normal procedures.

At operation 4, the C-SGN 306 performs a Location Update to the HSS 310 including the reason for Location Update, e.g., MT SMS. The HSS 310 will inform the C-SGN 306 that there are N messages to be sent to the UE.

At operation 5, the C-SGN 306 establishes UE context indicating to RAN node that SRB is needed and without requesting DRBs to be established.

At operations 6 and 7, RRC message establishes SRB.

At operation 8, S1 message is acknowledged.

At operation 9, the HSS 310 alerts the SMSC 308 that the UE 302 is available per procedures defined in 3GPP 29.002.

At operation 10 a, the SMSC 308 sends the 1st SMS PDU to the C-SGN 306.

At operation 10 b, the SMSC 308 sends the 2nd SMS PDU to the C-SGN 306.

At operation 10 n, the SMSC 308 sends the nth SMS PDU to the C-SGN 306. In some implementations, the SM could come from numerous different SMS-C's.

At operation 11, when the C-SGN 306 receives the 1st SMS PDU from the SMSC 308, the C-SGN 306 sends Attach Accept including the SMS PDU as defined in 3GPP TS 23.040 to the UE 302 and an indication of the number of outstanding SM to be sent to the UE 302.

At operation 12, MO and MT SMS procedures following the procedures defined in TS 23.060 are performed while utilizing the small data transfer described other sections.

At operation 13, when the UE 302 has received the number of outstanding SM as identified in operation 11 from the C-SGN 306, the UE 302 shall send a Detach to the C-SGN 306.

FIG. 6 is a schematic diagram illustrating an example process 600 of a UE including mobile-originated data in a Message 1 according to an implementation. The Message 1 may be an attach request message. For example, the UE 102 includes the mobile-originated data in the field of user data (UD) 602 of an SMS-SUBMIT PDU, and further includes the SMS-SUBMIT PDU in the field of user data length (UDL) and UD 608 of the attach request message 610. The UE includes the SMSC address in the field of destination address (DA) 606 of the attach request message 610. The attach request message 610 to be sent to a network node 1 (e.g., C-SGN) also includes attach information 604.

FIG. 7 is a schematic diagram illustrating an example process 700 of a network node 1 extracting mobile-originated data from a Message 1 and including the data in a Message 7 according to an implementation. The network node 1 may be a C-SGN. The Message 1 may be an attach request message. The schematic diagram includes an attach request message 702 received from the UE and a Message 7 710 to be sent to a network node 3 (e.g., SMS-C). For example, the attach request message 702 received at the C-SGN includes the SMSC address included in the DA field 704 and the mobile-originated data included in the UDL and UD field 706. The C-SGN extracts the mobile-originated data from the attach request message 702 and includes the data in the UD field 712 of the Message 7 710. Message 7 710 also includes the SMSC address in the DA field 708 of the UD field 712.

FIG. 8 is a schematic diagram illustrating an example process 800 of a network node 1 extracting mobile-terminated data from a Message 3 c and including the data in a Message 6 according to an implementation. The network node 1 may be a C-SGN. The Message 6 may be an attach response message, which may be an attach reject or accept. The schematic diagram includes a Message 3 c 802 received from a network node 3 (e.g., SMSC) and an attach response message 816 to be sent to the UE. For example, the Message 3 c 802 received from the SMSC includes a UD field 804. The UD field 804 further includes an SMS-DELIVER PDU with the mobile-terminated data included in a UD field 808 of the SMS-DELIVER PDU. The C-SGN extracts the SMS-DELIVER PDU from the Message 3 c 802 and includes the PDU in a UDL and UD field 814 of an attach response message 816. The C-SGN also includes the SMSC address in a field of originator address (OA) 812 of the attach response message 816. The C-SGN obtains the SMSC address from an OA field 806 of the UD field 804 in the Message 3 c 802. The attach response message 816 also includes attach reject or accept information 810.

FIG. 9 is a schematic diagram illustrating an example process 900 of a UE extracting mobile-terminated data from a Message 6 according to an implementation. The Message 6 may be an attach response message, which may be an attach reject or accept. For example, the UE receives an attach response message 902 from a network node 1 (e.g., C-SGN). The attach response message 902 may include attach reject or accept information 904, the SMSC address in the OA field 906, and a UDL and UD field 908. The UDL and UD field 908 may further include an SMS-DELIVER PDU with the mobile-terminated data included in a UD field 910 of the SMS-DELIVER PDU. The UE extracts mobile-terminated data from the SMS-DELIVER PDU in the attach response message 902.

FIG. 10 is a schematic diagram illustrating an example process 1000 of a UE including mobile-originated data in a Message 1 without an SMSC address according to an implementation. The Message 1 may be an attach request message. For example, the UE includes the mobile-originated data in the field of user data (UD) 1002 of an SMS-SUBMIT PDU, and further includes the SMS-SUBMIT PDU in the field of user data length (UDL) and UD 1006 of the attach request message 1008. The UE does not include an SMSC address in the attach request message 1008. The attach request message 1008 to be sent to a network node 1 (e.g., C-SGN) also includes attach information 1004.

FIG. 11 is a schematic diagram illustrating an example process 1100 of a network node 1 extracting mobile-originated data from a Message 1 and including the data in a Message 7, without a UE providing an SMSC address, according to an implementation. The network node 1 may be a C-SGN. The Message 1 may be an attach request message. The schematic diagram includes an attach request message 1102 received from the UE and a Message 7 1108 to be sent to a network node 3 (e.g., SMSC). For example, the attach request message 1102 received at the C-SGN includes the mobile-originated data included in the UDL and UD field 1104. The C-SGN extracts the mobile-originated data from the attach request message 702 and includes the data in the UD field 1110 of the Message 7 1108. The attach request message 1102 does not include an SMSC address. The C-SGN may include the SMSC address that was received from Message 3 e into Message 7 1108. For example, the SMSC address may be included in the DA field 1106 of the UD field 1110 of the Message 7 1108.

FIG. 12 is a schematic diagram illustrating an example process 1200 of a network node 1 extracting mobile-terminated data from a Message 3 c and including the data in a Message 6 without a SMSC address, according to an implementation. The network node 1 may be a C-SGN. The Message 6 may be an attach response message, which may be an attach reject or accept. The schematic diagram includes a Message 3 c 1202 received from a network node 3 (e.g., SMSC) and an attach response message 1212 to be sent to the UE. For example, the Message 3 c 1202 received from the SMSC includes a UD field 1204. The UD field 1204 further includes an SMS-DELIVER PDU with the mobile-terminated data included in a UD field 1206 of the SMS-DELIVER PDU. The C-SGN extracts the SMS-DELIVER PDU from the Message 3 c 1202 and includes the PDU in a UDL and UD field 1210 of an attach response message 1212. The C-SGN does not include an SMSC address in the attach response message 1212. The attach response message 1212 also includes attach reject or accept information 1208.

FIG. 13 is a schematic diagram illustrating an example process 1300 of a UE extracting mobile-terminated data from a Message 6 without an SMSC address according to an implementation. The Message 6 may be an attach response message, which may be an attach reject or accept. For example, the UE receives an attach response message 1302 from a network node 1 (e.g., C-SGN). The attach response message 1302 may include attach reject or accept information 1304 and a UDL and UD field 1306. The UDL and UD field 1306 further include an SMS-DELIVER PDU with the mobile-terminated data included in a UD field 1308 of the SMS-DELIVER PDU. The UE extracts mobile-terminated data from the SMS-DELIVER PDU in the attach response message 1302. The attach response message 1302 does not include an SMSC address.

FIG. 14 is a flowchart illustrating an example method 1400 for using optimized short message transport to transfer data in a CIoT environment according to an implementation. The method 1400 may begin at block 1402, where the first network node receives an attach request message from a UE. The attach request message includes short-message data and indicates a type of service the UE requested. The short-message data is one or more PDUs that are at least one of an SMS-SUBMIT PDU, an SMS-COMMAND PDU, an SMS-DELIVER-REPORT PDU, or an SMS-SUBMIT-REPORT PDU. The type of data service may be one of but not limited to mobile origination, mobile termination, or mobile origination and termination. At block 1404, the first network node sends a message to a second network node and the message indicates the type of service the UE requested.

At block 1406, the first network node receives a short-message data response message from the second network node. The short-message data response message may include at least one of an address for a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, the number of mobile-terminated messages pending for the UE, or a short-message entity destination address.

At block 1408, the first network node may transmit an attach response message to the UE. The attach response message may indicate whether a message for the UE is pending and/or the number of pending messages. The attach response message may also include the mobile-terminated message.

At block 1410, the first network node determines the short-message service center based on the address included in the short-message data response. In response to the determining, the first network node transmits the short-message data to the short-message service center.

FIG. 15 is a data flow diagram illustrating an example process 1500 to notify a network node 2 of a number of mobile-terminated messages pending according to an implementation. The data flow diagram includes a network node 2 108 (e.g., HSS) and a network node 3 110 (e.g., SMSC).

At operation 10, if a mobile-terminated message cannot be delivered to the UE, the network node 3 110 may send a Message 10 to the network node 2 108. The Message 10 may include the identity of the UE (e.g., the private identity such as IMSI or GUTI or the public identity such as MSISDN or URI) and/or the number of pending messages to be delivered to the UE. Upon receiving the Message 10, the network node 2 may store the identity of the UE and/or the number of pending messages to be delivered. At operation 11, the network node 2 108 may send a Message 11 to the network node 3 110 to acknowledge the receipt of Message 10. In some implementations, the example process 1500 may occur when the UE is not connected to the network.

FIGS. 16A-16E illustrate a first example description of Evolved Packet System (EPS) mobility management (EMM) procedures according to an implementation. For example, the attach procedure in 3GPP TS 24.302 may include the following description when the UE attaches to the network for CIoT SMS services (also known as optimized short message transport):

If the UE is CIoT capable, the network is CIoT capable (see description below) and the UE wants to

a) send a SM, then the UE shall send the ATTACH REQUEST message together with SMS-SUBMIT message as defined in 3GPP 23.040 [x] contained in the CIoT message container information element. The UE shall set the Attach type to “SMS MO”.

b) receive an SM, then the UE shall send the ATTACH REQUEST message. The UE shall set the Attach type to “SMS MT; or

c) send and receive an SM, then the UE shall send the ATTACH REQUEST message together with SMS-SUBMIT message as defined in 3GPP 23.040 [x] contained in the CIoT message container information element. The UE shall set the Attach type to “SMS MO/MT”.

FIGS. 17A-17F illustrate a second example description of EMM procedures according to an implementation. For example, the attach procedure in 3GPP TS 24.302 may include the following description of MME (i.e., the network node 1) behavior when an attach request of CIoT SMS services is accepted by the network:

If the attach request is accepted by the network, the MME shall send an ATTACH ACCEPT message to the UE and start timer T3450. If the UE indicated:

-   -   a) EPS attach, combined EPS/IMSI attach then the MME shall send         the ATTACH ACCEPT message together with an ACTIVATE DEFAULT EPS         BEARER CONTEXT REQUEST message contained in the ESM message         container information element to activate the default bearer         (see subclause 6.4.1). The network may also initiate the         activation of dedicated bearers towards the UE by invoking the         dedicated EPS bearer context activation procedure (see subclause         6.4.2).     -   b) SMS MO, the MME shall send an ATTACH REJECT message with         -   i) If the UE indicated the Attach type to “SMS MO” and the             CIoT message container information element contained SMS PDU             as defined in 3GPP TS 23.040 [x], EMM cause code set to             -   1) “Successful receipt of data” if there are no pending                 messages to be delivered to the UE; or             -   2) “successful receipt of data, and pending messages to                 send” if there are pending messages to be delivered to                 the UE.         -   ii) If the UE indicated the Attach type to “SMS MO” and the             CIoT message container information element does not contain             an SMS PDU as defined in 3GPP TS 23.040 [x] or the CIoT             message contained information element is not present, EMM             cause code set to             -   1) “data not received” if there are no pending messages                 to be delivered to the UE; or             -   2) “data not received and pending data to send” if there                 are pending messages to be delivered to the UE;     -   c) SMS MT the MME shall send ATTACH REJECT message with         -   i) If the UE indicated the Attach type to “SMS MT”, EMM             cause code set to “no pending terminated messages to send”             if there are no pending messages to be delivered to the UE.     -   d) SMS MT the MME shall send ATTACH ACCEPT message with:         -   i) If the UE indicated the Attach type to “SMS MT” and, EMM             cause code set to             -   1) “no pending terminated messages” if there is a single                 SMS MT PDU as defined in 3GPP TS 23.040 [x] and include                 the SMS MT PDU as defined in 3GPP TS 23.040 [x] in the                 CIoT message container information element.             -   2) “pending messages to send” if there are more than one                 SMS MT PDU as defined in 3GPP TS 23.040 [x] and include                 the first SMS MT PDU as defined in 3GPP TS 23.040 [x] in                 the CIoT message container information element.             -   ALTERNATIVE TO d)2)     -   d) SMS MT the MME shall send ATTACH ACCEPT message with         -   i) if there is a single SMS MT PDU as defined in 3GPP TS             23.040 [x] and include the SMS MT PDU as defined in 3GPP TS             23.040 [x] in the CIoT message container information             element.         -   ii) if there are more than one SMS MT PDU as defined in 3GPP             TS 23.040 [x] and include             -   1) the first SMS MT PDU as defined in 3GPP TS 23.040 [x]                 in the CIoT message container information element; and                 the Pending Messages information element with the number                 of pending messages to send.     -   e) SMS MO/MT the MME shall send an ATTACH REJECT message         -   i) If the UE indicated the Attach type to “SMS MO/MT” and             the CIoT message container information element contained SMS             PDU as defined in 3GPP TS 23.040 [x], EMM cause code set to             -   1) “Successful receipt of data” if there are no pending                 messages to be delivered to the UE; or             -   ALTERNATIVE TO e)i1)             -   1) “successful receipt of data, and no pending messages                 to send” if there are no pending messages to be                 delivered to the UE; or         -   ii) If the UE indicated the Attach type to “SMS MO” and the             CIoT message container information element does not contain             an SMS PDU as defined in 3GPP TS 23.040 [x] or the CIoT             message container information element is not present, EMM             cause code set to             -   1) “data not received” if there are no pending messages                 to be delivered to the UE;             -   2) “data not received, pending messages to send” if                 there are pending messages to be delivered to the UE             -   ALTERNATIVE TO e)ii1)             -   1) “data not received, no pending messages to send” if                 there are no pending messages to be delivered to the UE;     -   f) SMS MO/MT the MME shall send an ATTACH ACCEPT message         -   i) If the UE indicated the Attach type to “SMS MO/MT” and             the CIoT message container information element contained SMS             PDU as defined in 3GPP TS 23.040 [x], EMM cause code set to             “Successful receipt of data” and if there             -   1) is a single SMS MT PDU as defined in 3GPP TS 23.040                 [x] include the SMS MT PDU as defined in 3GPP TS 23.040                 [x] in the CIoT message container information element.             -   2) if there are more than one SMS MT PDU as defined in                 3GPP TS 23.040 [x] include the first SMS MT PDU as                 defined in 3GPP TS 23.040 [x] in the CIoT message                 container information element; and the Pending Messages                 information element with the number of pending messages                 to send

FIG. 18 illustrates a third example description of EMM procedures according to an implementation. For example, the attach procedure in 3GPP TS 24.302 may include the following description of UE behavior upon the UE receiving an attach reject message:

The UE shall take the following actions depending on the EMM cause value received in the ATTACH REJECT message.

-   -   #3 (Illegal UE);     -   #6 (Illegal ME); or     -   . . .     -   #XX (data not receive);         -   The UE shall repeat the ATTACH procedure for CIoT device up             to a maximum number of times.     -   #XX (data not receive, no pending messages to send);         -   The UE shall repeat the ATTACH procedure and UE shall set             the Attach type to “SMS MO”     -   #XX (data not received and pending data to send);         -   The UE shall repeat the ATTACH procedure and UE shall set             the Attach type to “SMS MO/MT”.     -   #XX (successful receipt of data, and pending messages to send);         -   The UE shall repeat the ATTACH procedure and UE shall set             the Attach type to “SMS MT”

FIGS. 19A and 19B illustrate an example description of an attach accept message according to an implementation. For example, the attach accept message in 3GPP TS 24.302 may include the following information elements (IEs):

TABLE 2 IEs in Attach Accept Message IEI Information Element Type/Reference Presence Format Length CiOT Message CloT Message O LV-E 5-n 9.9.3.XX EMM cause EMM cause O V 1 9.9.3.9 Pending messages Pending messages O TV 2 9.9.3.YY

FIG. 20 illustrates an example description of an attach reject message according to an implementation. For example, the attach reject message in 3GPP TS 24.302 may include the following IE:

TABLE 3 IE in Attach Reject Message IEI Information Element Type/Reference Presence Format Length CiOT Message CioT Message O LV-E 5-n 9.9.3.XX

FIGS. 21A and 21B illustrate an example description of an attach request message according to an implementation. For example, the attach request message in 3GPP TS 24.302 may include the following IE:

TABLE 4 IEs in Attach Request Message IEI Information Element Type/Reference Presence Format Length CiOT Message CioT Message O LV-E 5-n 9.9.3.XX Pending messages Pending messages O TV 2 9.9.3.YY

FIGS. 22A and 22B illustrate an example description of EMM cause according to an implementation. For example, the following causes may be included in 3GPP TS 24.302:

TABLE 5 EMM Causes   successful receipt of data no pending terminated messages data not received data not received, no pending messages to send data not received, pending messages to send Pending data to send successful receipt of data, and pending messages to send successful receipt of data, and no pending messages to send

FIG. 23 illustrates an example description of EPS attach type according to an implementation. For example, the following EPS attach type may be included in 3GPP TS 24.302:

TABLE 6 EPS Attach Type Information Element EPS attach type value (octet 1) Bits 3 2 1 0 0 1 EPS attach 0 1 0 combined EPS/IMSI attach 1 1 0 EPS emergency attach 1 1 1 reserved All other values are unused and shall be interpreted as “EPS attach”, if received by the network. Bit 4 of octet 1 When coded as 1 indicates attach type has been extended

TABLE 7 EPS Attach Type Value EPS attach type value (octet 2) Bits 3 2 1 0 0 1 EPS attach for CioT 0 1 0 SMS data attach 1 1 0 reserved 1 1 1 reserved All other values are unused and shall be interpreted as “EPS attach for CioT”, if received by the network. Bit 4-8 of octet 2 spare and coded as zero

Other values could be

1. SMS MO attach

2. SMS MT attach

3. SMS MO/MT attach

FIG. 24 illustrates an example description of a CIoT message container according to an implementation. For example, the following description of the CIoT message container may be included in 3GPP TS 24.302:

CioT Message Container

This purpose of the CioT message container is to transfer of small data within an EMM message. The following IEI values are defined:

TABLE 8 CIOT Message Types for EPS Mobility Management Bits 8 7 6 5 4 3 2 1 0 1 — — — — — — SMS message container 1 0 USSD message container

FIG. 25 illustrates an example description of data message container IE according to an implementation. For example, the following description of the data message container IE may be included in 3GPP TS 24.302:

Data Message Container Information Element

The purpose of the Data message container information element is to enable transfer of a Data message within an EMM message e.g. SMS or USSD. SMS payload is defined within 3GPP TS 23.040. The SMS message included in this IE shall be coded as specified in subclause 8.3, i.e. without NAS security header.

The SMS message container information element is coded as shown below.

TABLE 9 Data Message Container Information Element 8 7 6 5 4 3 2 1 CIOT Message types for EPS mobility management container IEI octet 1 Length of Data message container contents octet 2 octet 3 Data message container contents octet 4 octet n

TABLE 10 Description of Data Message Container Information Element SMS message container contents (octet 4 to octet n); Max value of YYY octets This IE can contain any SMS PDU as defined in 3GPP TS 23.040.

FIG. 26 illustrates an example description of pending messages IE according to an implementation. For example, the following description of pending messages IE may be included in 3GPP TS 24.302:

Pending Messages

The purpose of this information element is to indicate the number of messages to be sent or received by the UE.

TABLE 11 Pending Messages Information Element 8 7 6 5 4 3 2 1 Pending message container IEI octet 1 Number of pending messages octet 2

FIGS. 27A-27C illustrate an example description of MAP_SEND_AUTHENTICATION_INFO service according to an implementation. For example, the following service primitives of MAP_SEND_AUTHENTICATION_INFO service may be included in 3GPP TS 29.002:

TABLE 12 MAP_SEND_AUTHENTICATION_INFO Parameters Parameter name Request Indication Response Confirm SMS only indicator C C(=) Pending messages to send C C

SMS Only Indicator

This parameter indicates if the UE has requested to attach for sending and/or receiving Short Messages.

OR

This parameter indicates if the UE has requested to attach for SMS.

Pending Messages to Send

This parameter shall be present if the HS S/HLR is aware of one or more Short Messages that are to be sent to the UE. This parameter shall be absent if the HSS/HLR is unaware of any Short Messages that are to be sent to the UE.

OR:

A number indicating how many Short Messages the UE shall be prepared to receive before performing a network detach.

FIGS. 28A-28C illustrate an example description of MAP_UPDATE_LOCATION service according to an implementation. For example, the following service primitives of MAP_UPDATE_LOCATION service may be included in 3GPP TS 29.002:

TABLE 13 MAP_UPDATE_LOCATION Parameters Parameter name Request Indication Response Confirm SMS only indicator C C(=) Pending messages to send C C SMS only indicator This parameter indicates if the UE has requested to attach for sending and/or receiving Short Messages.

OR

This parameter indicates if the UE has requested to attach for SMS.

Pending Messages to Send

This parameter shall be present if the HS S/HLR is aware of one or more Short Messages that are to be sent to the UE. This parameter shall be absent if the HSS/HLR is unaware of any Short Messages that are to be sent to the UE.

OR:

A number indicating how many Short Messages the UE shall be prepared to receive before performing a network detach.

FIGS. 29A-29C illustrate an example description of MAP_UPDATE_GPRS_LOCATION service according to an implementation. For example, the following service primitives of MAP_UPDATE_GPRS_LOCATION service may be included in 3GPP TS 29.002:

TABLE 14 MAP_UPDATE_GPRS_LOCATION Parameters Parameter name Request Indication Response Confirm SMS only indicator C C(=) Pending messages to send C C

SMS Only Indicator

This parameter indicates if the UE has requested to attach for sending and/or receiving Short Messages.

OR

This parameter indicates if the UE has requested to attach for SMS.

Pending Messages to Send

This parameter shall be present if the HS S/HLR is aware of one or more Short Messages that are to be sent to the UE. This parameter shall be absent if the HSS/HLR is unaware of any Short Messages that are to be sent to the UE.

OR:

A number indicating how many Short Messages the UE shall be prepared to receive before performing a network detach.

FIGS. 30A-30C illustrate an example description of MAP-INSERT-SUBSCRIBER-DATA service according to an implementation. For example, the following service primitives of MAP-INSERT-SUBSCRIBER-DATA service may be included in 3GPP TS 29.002:

TABLE 15 MAP-INSERT-SUBSCRIBER-DATA Parameter Parameter name Request Indication Response Confirm Pending messages to send C C(=)

Pending Messages to Send

This parameter shall be present if the HS S/HLR is aware of one or more Short Messages that are to be sent to the UE. This parameter shall be absent if the HSS/HLR is unaware of any Short Messages that are to be sent to the UE.

OR:

A number indicating how many Short Messages the UE shall be prepared to receive before performing a network detach.

FIGS. 31A and 31B illustrate an example description of MAP-REPORT-SM-DELIVERY-STATUS service according to an implementation. For example, the following service primitives of MAP-REPORT-SM-DELIVERY-STATUS service may be included in 3GPP TS 29.002:

TABLE 16 MAP-REPORT-SM-DELIVERY-STATUS Parameter Parameter name Request Indication Response Confirm Pending messages to send C C(=)

Pending Messages to Send

This parameter shall be present if the HS S/HLR is aware of one or more Short Messages that are to be sent to the UE. This parameter shall be absent if the HSS/HLR is unaware of any Short Messages that are to be sent to the UE.

OR:

A number indicating how many Short Messages the UE shall be prepared to receive before performing a network detach.

FIG. 32 illustrates an example description of mobile service data type according to an implementation. For example, the following description of mobile service data type may be included in 3GPP TS 29.002:

TABLE 17 SendAuthenticationInfoArg Description SendAuthenticationInfoArg ::= SEQUENCE {  imsi [0] IMSI,  numberOfRequestedVectors NumberOfRequestedVectors,  segmentationProhibited NULL OPTIONAL,  immediateResponsePreferred [1] NULL  OPTIONAL,  re-synchronisationInfo Re-synchronisationInfo OPTIONAL,  extensionContainer [2] ExtensionContainer OPTIONAL,  ...,  requestingNodeType [3] RequestingNodeType OPTIONAL,  requestingPLMN-Id [4] PLMN-Id OPTIONAL,  numberOfRequestedAdditional-Vectors [5] NumberOfRequestedVectors OPTIONAL,  additionalVectorsAreForEPS [6] NULL OPTIONAL,  sMS-OnlyIndicator [7] SMS-OnlyIndicator }

TABLE 18 SMS-OnlyIndicator Description   SMS-OnlyIndicator ::= ENUMERATED { MO (0), Mt  (1), MOandMT  (3) ... } If the “Pending messages to send” IE is a simple flag/indicator:

TABLE 19 SendAuthenticationInfroRes Description with a Simple Flag of Pending Messages SendAuthenticationInfoRes ::= [3] SEQUENCE {  authenticationSetList AuthenticationSetList OPTIONAL,  extensionContainer ExtensionContainer OPTIONAL,  ...,  eps-AuthenticationSetList [2] EPS-AuthenticationSetList OPTIONAL,  pendingMessagesToSend [3] NULL OPTIONAL } If the “Pending messages to send” IE indicates the number of messages that are to be sent to the UE (e.g. as stored in the HSS/HLR):

TABLE 20 SendAuthenticationInfoRes Description with a Number of Pending Messages SendAuthenticationInfoRes ::= [3] SEQUENCE {  authenticationSetList AuthenticationSetList OPTIONAL,  extensionContainer ExtensionContainer OPTIONAL,  ...,  eps-AuthenticationSetList [2] EPS-AuthenticationSetList OPTIONAL,  pendingMessagesToSend [3] PendingMessagesToSend OPTIONAL }

TABLE 21 NumberOfPendingMessagesToSend Description   NumberOfPendingMessagesToSend ::= INTEGER (0..MaxNumberOfPendingMessagesToSend)

TABLE 22 MaxNumberOfPendingMessagesToSend Description   MaxNumberOfPendingMessagesToSend ::= 255

FIG. 33 is a schematic illustrating an example network node 3300. The example network node 3300 includes a processing module 3302, a wired communication subsystem 3304, and a wireless communication subsystem 3306. The processing module 3302 can include one or more processing components (alternatively referred to as “processors” or “central processing units” (CPUs)) operable to execute instructions associated with managing inter-device communications. The processing module 3302 can also include other auxiliary components, such as random access memory (RAM), read-only memory (ROM), secondary storage (for example, a hard disk drive or flash memory). The processing module 3302 can execute certain instructions and commands to provide wireless or wired communication, using the wired communication subsystem 3304 or a wireless communication subsystem 3306. A skilled artisan will readily appreciate that various other components can also be included in the example network node 3300.

FIG. 34 is a schematic illustrating an example UE apparatus. The example UE 3400 includes a processing unit 3402, a computer-readable storage medium 3404 (for example, ROM or flash memory), a wireless communication subsystem 3406, an interface 3408, and an I/O interface 3410. The wireless communication subsystem 3406 may be configured to provide wireless communications for data information or control information provided by the processing unit 3402. The wireless communication subsystem 3406 can include, for example, one or more antennas, a receiver, a transmitter, a local oscillator, a mixer, and a digital signal processing (DSP) unit. The interface 3408 can include, for example, one or more of a screen or touch screen (for example, a liquid crystal display (LCD), a light emitting display (LED), an organic light emitting display (OLED), a microelectromechanical system (MEMS) display), a keyboard or keypad, a trackball, a speaker, and a microphone. The I/O interface 3410 can include, for example, a universal serial bus (USB) interface. A skilled artisan will readily appreciate that various other components can also be included in the example UE device 3400.

While operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be employed. Moreover, the separation of various system components in the implementation descried above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a signal software product or packaged into multiple software products.

Also, techniques, systems, subsystems, and methods described and illustrated in the various implementations as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made.

While the above detailed description has shown, described, and pointed out the fundamental novel features of the disclosure as applied to various implementations, it will be understood that various omissions, substitutions, and changes in the form and details of the system illustrated may be made by those skilled in the art. In addition, the order of method steps are not implied by the order they appear in the claims. 

What is claimed is:
 1. A method, comprising: receiving, at a first network node, an attach request message, wherein the attach request message includes short-message data; receiving, from a second network node, a short-message data response message, wherein the short-message data response message includes at least one of an address for a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, or a short-message entity destination address.
 2. The method of claim 1, wherein the short-message data is one or more Protocol Data Units (PDUs) that are at least one of a short-message service (SMS)-SUBMIT PDU, an SMS-COMMAND PDU, an SMS-DELIVER-REPORT PDU, or an SMS-SUBMIT-REPORT PDU.
 3. The method of claim 1, wherein the attach request message indicates a type of service for transmitting the short-message data.
 4. The method of claim 1, wherein the attach request message indicates that the UE requests not to transition to a connected mode.
 5. The method of claim 1, further comprising: sending a second message to the second network node, wherein the second message indicates a type of service for transmitting the short-message data.
 6. The method of claim 5, wherein the second message is at least one of an authentication request or a location update.
 7. The method of claim 1, wherein the short-message data response message comprises an insert subscriber data (ISD).
 8. The method of claim 1, further comprising: transmitting an attach response message to the UE, wherein the attach response message indicates whether a message for the UE is pending.
 9. The method of claim 1, wherein the short-message data response message includes an address for a short-message service center, and the method further comprises: determining the short-message service center based on the address included in the short-message data response; and in response to the determining, transmitting the short-message data to the short-message service center.
 10. A device, comprising: a memory; and at least one hardware processor communicatively coupled with the memory and configured to: receive, at a first network node, an attach request message, wherein the attach request message includes short-message data; receive, from a second network node, a short-message data response message, wherein the short-message data response message includes at least one of an address for a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, or a short-message entity destination address.
 11. The device of claim 10, wherein the short-message data is one or more Protocol Data Units (PDUs) that are at least one of a short-message service (SMS)-SUBMIT PDU, an SMS-COMMAND PDU, an SMS-DELIVER-REPORT PDU, or an SMS-SUBMIT-REPORT PDU.
 12. The device of claim 10, wherein the attach request message indicates a type of service for transmitting the short-message data.
 13. The device of claim 10, wherein the attach request message indicates that the UE requests not to transition to a connected mode.
 14. The device of claim 10, wherein the at least one hardware processor is further configured to: send a second message to the second network node, wherein the second message indicates a type of service for transmitting the short-message data.
 15. The device of claim 14, wherein the second message is at least one of an authentication request or a location update.
 16. The device of claim 10, wherein the short-message data response message comprises an insert subscriber data (ISD).
 17. The device of claim 10, wherein the at least one hardware processor is further configured to: transmit an attach response message to the UE, wherein the attach response message indicates whether a message for the UE is pending.
 18. The device of claim 10, wherein the short-message data response message includes an address for a short-message service center, and the at least one hardware processor is further configured to: determine the short-message service center based on the address included in the short-message data response; and in response to the determining, transmit the short-message data to the short-message service center.
 19. A tangible, non-transitory computer-readable medium containing instructions which, when executed, cause a computing device to perform operations comprising: receiving, at a first network node, an attach request message, wherein the attach request message includes short-message data; receiving, from a second network node, a short-message data response message, wherein the short-message data response message includes at least one of an address for a short message service center, an indication that indicates no mobile-terminated message is pending for the UE, or a short-message entity destination address. 20-21. (canceled) 